I think my settings are a bit confusing, or I didn’t do a good job of explaining it in the documentation. Someone else had emailed me privately last month having the same “issue”, but they simply didn’t understand the way the settings work.
If you want the “View & Signup” link on the calendar to go to the regular list page (not the calendar page) for signing up, as opposed to enabling the pop-up signup form on the calendar itself, then you MUST have a page set in the main plugin’s settings for the dropdown select setting that says:
Volunteer Sign Up Page
That’s the third setting from the top on the Main Settings tab of the main/free plugin.
If you don’t have a page set there, then the View & Signup link doesn’t have a destination to go to, so it will stay on the same page (the Calendar) and just append those arguments to the current page URL.
Based on the URL you included, that indeed looks to be the case since it is going to the /signup-calendar/ page, which is where I assume you have the calendar shortcode.